net: mdio-gpio: Add support for separate MDI and MDO gpio pins

This is for a system with fixed assignments of input and output pins
(various variants of Kontron COMe).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 3 deletions

diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index fac211a5001e..9c4defdec67b 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -32,8 +32,8 @@
 
 struct mdio_gpio_info {
         struct mdiobb_ctrl ctrl;
-        int mdc, mdio;
-        int mdc_active_low, mdio_active_low;
+        int mdc, mdio, mdo;
+        int mdc_active_low, mdio_active_low, mdo_active_low;
 };
 
 static void *mdio_gpio_of_get_data(struct platform_device *pdev)
@@ -60,6 +60,12 @@ static void *mdio_gpio_of_get_data(struct platform_device *pdev)
         pdata->mdio = ret;
         pdata->mdio_active_low = flags & OF_GPIO_ACTIVE_LOW;
 
+        ret = of_get_gpio_flags(np, 2, &flags);
+        if (ret > 0) {
+                pdata->mdo = ret;
+                pdata->mdo_active_low = flags & OF_GPIO_ACTIVE_LOW;
+        }
+
         return pdata;
 }
 
@@ -68,6 +74,16 @@ static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
         struct mdio_gpio_info *bitbang =
                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 
+        if (bitbang->mdo) {
+                /* Separate output pin. Always set its value to high
+                 * when changing direction. If direction is input,
+                 * assume the pin serves as pull-up. If direction is
+                 * output, the default value is high.
+                 */
+                gpio_set_value(bitbang->mdo, 1 ^ bitbang->mdo_active_low);
+                return;
+        }
+
         if (dir)
                 gpio_direction_output(bitbang->mdio,
                                       1 ^ bitbang->mdio_active_low);
@@ -88,7 +104,10 @@ static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
         struct mdio_gpio_info *bitbang =
                 container_of(ctrl, struct mdio_gpio_info, ctrl);
 
-        gpio_set_value(bitbang->mdio, what ^ bitbang->mdio_active_low);
+        if (bitbang->mdo)
+                gpio_set_value(bitbang->mdo, what ^ bitbang->mdo_active_low);
+        else
+                gpio_set_value(bitbang->mdio, what ^ bitbang->mdio_active_low);
 }
 
 static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
@@ -125,6 +144,8 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
         bitbang->mdc_active_low = pdata->mdc_active_low;
         bitbang->mdio = pdata->mdio;
         bitbang->mdio_active_low = pdata->mdio_active_low;
+        bitbang->mdo = pdata->mdo;
+        bitbang->mdo_active_low = pdata->mdo_active_low;
 
         new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
         if (!new_bus)
@@ -151,6 +172,13 @@ static struct mii_bus *mdio_gpio_bus_init(struct device *dev,
         if (devm_gpio_request(dev, bitbang->mdio, "mdio"))
                 goto out_free_bus;
 
+        if (bitbang->mdo) {
+                if (devm_gpio_request(dev, bitbang->mdo, "mdo"))
+                        goto out_free_bus;
+                gpio_direction_output(bitbang->mdo, 1);
+                gpio_direction_input(bitbang->mdio);
+        }
+
         gpio_direction_output(bitbang->mdc, 0);
 
         dev_set_drvdata(dev, new_bus);